list = Array.new(1000){0}

script = ARGF.readlines.map{|x|x.chomp}.join
puts script
ptr = 0
pos = 0
parents = []

loop do
  case script[pos]
  when '>'.sum #increment pointer
    ptr += 1
    pos += 1
  when '<'.sum #decrement pointer
    ptr -= 1
    pos += 1
  when '+'.sum #increment list of pointer
    list[ptr] += 1
    pos += 1
  when '-'.sum #decrement list of pointer
    list[ptr] -= 1
    pos += 1
  when '.'.sum #putchar
    print list[ptr].chr
    pos += 1
  when ','.sum #getchar
    list[ptr] = STDIN.getc
    pos += 1
  when '['.sum #jump to next ] if list of pointer is 0
    if list[ptr] == 0
      if pair = lambda do |curpos|
          inner = 0
          while x = script[curpos+=1]
            case x
            when ']'.sum
              if inner > 0
                inner -= 1
              else
                return curpos
              end
            when '['.sum
              inner += 1
            end
          end
          nil
        end.call(pos)
        pos = pair + 1
      else
        raise "Missmatched open parenthes"
      end
    else
      parents.push pos
      pos += 1
    end
  when ']'.sum #jump to previews [
    raise "Missmatched close parenthes" if parents.empty?
    pos = parents.pop
  when nil #end script
    exit
  else
    warn "unkown charctor:" + script[pos,1]
    pos += 1
  end
  #print script[pos].chr
end